iPhone unlocking tool ultrasn0w working on iOS 4.2.1

Earlier this morning, dev-team member MuscleNerd tweeted that he, and his gang of merry men, have successfully tweaked their ultrasn0w iPhone unlocking tool to working on Apple’s latest mobile iOS iteration, 4.2.1. If you read further down the twitter timeline, it looks like — for the time being — ultrasn0w is only working on iPhone 3G/3GS handsets with a baseband of 05.15.04; the iPhone 4 uses a different baseband and still needs more work. Despite not having a one-stop unlock for all iPhones, the dev-team will release the working version of ultrasn0w for the iPhone 3G/3GS in the very near future — they will not make users of said handset wait until the iPhone 4 exploit is completed. Hit the jump for the two read links.